Accurately marking the position of a sunken object in water has been a difficult task. Usually a position is marked by placing a buoy as close as practicable to the position's location. The buoy most currently used is either free floating or is tethered via a single line to an anchor on the surface at the bottom of the water. Unfortunately this type buoy does not sufficiently constrain the motion of a buoy on the top of the water over a period of time since its position will vary within a large circle (watch circle) that is defined by the water current, tides, and length of the buoy's tether to the anchor.
The effects of current, tides, and length of the buoy's tether may make the size of the watch circle considerable in very shallow water (VSW) between 10 and 40 foot water depths, in the surf zone (SZ) between 0 and 10 foot water depths, and in the beach zone (BZ). This lack of definiteness is a disadvantage and can disrupt some operations because the actual position that the buoy is intended to mark cannot be exactly determined by visual means.
Some recent buoy system designs have incorporated global positioning system (GPS) transmitters so the buoy's position can be transmitted in GPS coordinates. However, because the buoy still has a large variance in its position, GPS coordinates of the buoy's position would have to be monitored over a long time period and averaged to determine the position it was intended to mark. This too may be flawed since a relatively constant unidirectional current flow over the same long period of time might still give an erroneous indication of where the correct buoy position is.
Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for buoy systems that maintain and identify positions visually on the surface of the water and transmit position data in GPS P(Y) code coordinates over a period of time such that reported positions are within three meters of actual positions.